Albert champion



A. CHAMPION.

SPARK PLUG. AAAAAAAA lON FILED'FEB. 26, 19420.

1,358,828. Patented N0v.16,1920

aww/nro@ I UNITED STATES PATENT OFFICE.

AIBERT 'CHAMPION'. 0F FLINT. MICHIGAN` ASQIGNOR TO CHAMPION IGNITION (JOM-k PANY, OF FLINT, MICHIGAN, A. CORPORATION OF MICHIGAN.

SPARK-PLUG.

Specification of Letters Patent.

Patented Nov. 16, 1920.

Application led February 26, 1920. Serial No. 361,401.

To all ywhom it may concern.

Be it known that I, ALBERT CHAMPION, a citizen of the United States, and a resident of Flint, county of Genesee, and State of Michigan, have invented certain new and useful Improvements in Spark-Plugs, of which the following is a full, clear, concise, and exact description, suoli as will enable others skilled in the art to which the invention relates to make and use the same, reference being made therein to the accompanying drawings, which form a part of this specification.

My invention relates to spark plugs designed for use with internal combustion engines to ignite the combustible mixture within the cylinder thereof, and wherein an insulator made of porcelain or equivalent material and which supports a central electrode is secured in place within a hollow external shell or casing which carries the outer electrode of the plug; and the principal object of my invention is to provide an improved snark plug comprising an external metallic shell or casing within which a porcelain insulator is located` and in which plug a better joint is secured between the porcelain or equivalent insulator and the external shell or casing thereof and leakage of gas between the insulator and the shell or casing the more effectively prevented when the plug is in use.

A further object of my invention is to provide an improved spark plug having an insulator securedin place within the metallic shell or casing thereof, and in which the insulator is less likely to become cracked or broken in assembling the plug and securing the insulator iii place within the casing than has heretofore commonly been the case.

A further ohiect of my invention is to provide a spark plug of the type above referred to and wherein the tendency of the porcelain or like insulator to rotate within the kmetallic .shell or casing thereof es the plug is assembled will be reduced to a minimum. and in which the insulator will in fact not rotate with'n the shell or casing as the saine is secured in place therein through and bv means of the usual gland nut employed in spark plugs for that purpose.

My improved spark plug is illustrated in its preferred form in the drawing accompanying and forming a part of thi specification; although it will be appreciated thit various changes, variations' and modifications may be made in the particular embodiment of my invention illustrated without departing from the spirit thereof, and that my invention includes all such variations and modifications of the particular embodiment thereof illustrated as come within the .scope of the concluding claims wherein the distinguishing features in which my invention consists are particularly pointed out.

Referring now to the drawing:

Figure 1 is a view showing my improved spark plug in side elevation, with certain portions broken away in order to better illustrate the construction and relationship of various of the features thereof.

Fig. Q is a fragmentary view showing the distinguishing features of my invention upon a considerably larger scale.

Fig. 3 is a view showing the metallic follower which enters into my invention, in perspective.

Fig. 4 is a similar view showing the lower or inner end of the gland nut of my improved spark plug` which engages theupper surface shown of the follower illustrated in Fig. 3.

In the drawing the reference numeral 5 designates the external shell or casing ofv mv improved spark plug, which is made of metal and is threaded at its lower' end as shown at 6 in order that the plug may be screwed in an opening provided for it in an internal combustion engine cylinder. This shell or casing is hollow, and the upper portion of the interior` thereof is threaded as shown at 7: and an internal annular ledge 8 is provided below said threaded portion and about midway of the length of the interior of the said shell.

Secured in place within the shell or casing is an insulator made, commonly, of porcelain or similar vitreous material. although it may obviously be made of mica or in fact of any suitable material having the requisite insulating qualities. The inner electrode of the plug extends through this insulator and is supported therehv. and said insulator is provided intermediate its length with a downwardly inclined annular peripherally extendingr lower Shoulder 10 which overlies the ledge 8 ofthe shell or casing and is supported by said ledge when the parts of the plug are assembled. The said insulator is alo provided with. a second p ripherallv extending annular upper fhouldcr 1l which lies adjacent the threads formed within thev Y the under side of which follower ,is inclined interior of the shell or casing adjacent thev upper end thereof, said shoulder bei-ng upwardly inclined fromthe periphery of the insulator in the form of my invention illustrated, and curved or concave in form 'to -thereby avoid sharp corners in the insulate..

inm'ember of the plug. Y n

' urrounding vthe upper end of the msulating member 9 is'an annular metallic lfollower 12 the upper surface of which is fiat and lies ina plane extending'substantially at -right ang-le Vto the axis ofthe Plug, and

in a manner similar to the inclination'of the upper shoulder V11 of the insulating mem ber; and the reference numeral 13-des1gnates a glandnut in threaded engagementwith the'threads provided at the upper end of the casing -5, Ythe. inner dia-meter o f the said gland nutV being somewhat greater than thatof the upwardly extending portion of the insulator so as not to bindrtherewithnas the glandi's rotated in assembling the plug to secure Athe insulator in place within the shell. The lower end of this gland is so shaped as to reduce the area of contact between the said lower end and the upper sur face of the follower 12 against which it abuts; the said gland in the form o f'my invention illustrated being beveled, as shown at la, to thereby .provide a narrowk annular extremity 15 which contacts with the upper surface of the follower along and throughout an annular band or zone 16 of small width as compared with the width of the upper surface of the follower, and which zone is located substantially midway between the inner and outer peripheries of the said follower, as illustrated in Fig. v3 of the'` drawing.

A suitable gasket 17 preferably yielding in characterso that it maybe compressed is interposed between the lower annular' Shoulder 10 and the ledge 8, and which gasket is compressed between said members when `the gland 13 is screwed downward and into the interior of the pluggand a second yieldable gasket 18 is also 'preferably provided between the underside of the follower 12 and the VY upper shoulder 11 of the insulating member 9, andthrough which lastinentioned gasket force is communicated to the insulator as the gland 'nut is rotated in assembling the plug, as will be appreciated. These gaskets form yieldable packings which prevent the outflow of gas from the interior'rof the cylinder of the engine, and

also 'prevent'` thel porcelain from .being cracked for broken as the gland nut is tightened because of the yieldable and cushion.L ingV properties.

rllhe reference numeral 19 designates the Vorner electrode of the plug which is secured in any suitable way Vto the lower end of the stell er were ,5i ses teegreteifeeeeeeeerel 20 designates the inner electrode which eX- tends through a passage formed in and *isr insulated by the insulator 9 these electrodes being so arranged that sparks pass between lthem when the plug is in use, aswill be un- .derstood V.ln view of the premises it will be appreciated that the force due to the screwing ofthe gland nut 13 into the hollow shell 5 in assembling the parts of the plug is communicated to thefannular follower 12 through a limited area at the extremity of said gland which results from the reduction4 of the sizeof the inner end of the said gland, and through the reduced annular band or zone 16 of small width located about midway the width of the upper surface of the said follower, as indicated in Fig. 3, with which the reduced inner end of the glandV contacts; and through the said-*follower to the porcelain vinsulator which is thus forced downward and against the gasket 17. This localization of the force communicated to the follower `from the Vgland along and throughouta comparatively narrow annular zone reduces the friction between the v gland and the follower, and prevents the follower from' rotating with the glandl and transmitting rotary movement to the insulator as the same isclamped in place within the shell, and provides aconstruction and Y,arrangement of spark plug in which the tightening of the gland asthe plug` is assembled will not communicate rotary motion to the insulator; from which it follows that during the securing of the insulator in place within the shell or casing Vno rotaryY move-V Y tion occurs or may occur during the screwing home of the gland whereby the insulator is forced against a ledge within the casing which supports the insulator of the plu and between which and a shoulder of the inf sulating member a yieldable packing is coinmonly interposed.

Having thus described and explained my invention, l claim and desire to secure by Letters Patenti' V1L ln a spark plug of the class described,

hollow metallic shell or casing interiorly Y threaded at its upper end and having an irfternaly downwardly inclined ledge below said threaded portion; an insulator arranged withieeidsliell@adhering e lower shoulder inclined similarly to and adapted to overlie said ledge, and an upper inclined shoulder adjacent the lower end of the 1n'- teriorly threaded portion of said shell; an annular metallic follower located within said shell and above the upper of the shoulders of said insulator and the under side of which is inclined similarly to said upper shoulder and the upper surface of which follower is in a plane substantially at right angles to the aXis of the plug; an exteriorly threaded gland in threaded engagement with the threaded portion aforesaid of said shell, and the lower end of which gland is reduced in size so as to provide a narrow annular area of contact between said lower end and the upper surface of said follower: and a gasket between the ledge aforesaid and the lower of the shoulders of said insulator.

2. In a spark plug of the class described, a hollow metallic shell or casing interiorly threaded at its upper end and having an in- "ernal ledge below said threaded portion; an insulator arranged within said shell and having a lower shoulder which overlies said ledge, and an upper shoulder; an annular metallic follower located within said shell and overlying the upper of the shoulders of said insulator, and the upper side of which follower is in a plane substantially at right angles to the axis of the plug; an exteriorly threaded'gland in threaded engagement with the threaded portion aforesaid of said shell and the lower end of which is of reduced l size and is so disposed as to contact with the upper surface of said follower about midway the width thereof, and throughout an annular band or zone of small width as compared with the width of said follower; and a gasket interposed between the ledge aforosaid and the lower of the shoulders of said insulator.

3. In a spark plug of the class described, a hollow metallic shell or casing interiorly threaded at its upper end and having an internal ledge below said threaded portion; an insulator located within said shell and having a lower shoulder adapted to overlie said ledge, and an upper shoulder adjacent thedower end of the interiorly threaded portion of said shell; an annular metallic follower located within said shell, and above the upper of the shoulders of said insulator; an exteriorly threaded gland in threaded engagement with the threaded portion aforesaid of said shell, and the lower end of which is beveled to provide a narrow annular area of contact between said lower end and the upper surface of said follower; a yieldable gasket between the ledge aforesaid and the lower of the shoulders of said insulator; and a second yieldable gasket between the under side of said follower and the upper of the shoulders of said insulator.

4. In a spark plug of the class described, a hollow metallic shell or casing interiorly threaded at its upper end and having an internal ledge below said threaded portion; an insulator located within said shell and having a lower shoulder adapted to overlie said ledge, and an upper shoulder; an annular metallic follower located within said shell and ,above the upper of the shoulders of said insulator; an exteriorly threaded gland in threaded engagement with the threaded portion aforesaid and the lower end of which engages the upper surface of said follower; a yieldable gasket between the ledge aforesaid and the lower of the shoulders of said insulator; and a second yieldable gasket between the under side of said follower and the upper of the shou1 ders of said insulator.

5. In a spark plug of the class described; a hollow metallic shell or casing having a threaded portion adjacent its up er end, and an internal annular ledge be ow said threaded portion; an insulator located within said shell and having a lower annular shoulder which overlies said ledge, and an upper shoulder; an annular metallic follower located within said shell and overlying the upper of the shoulders of said insulator, and the upper side of which follower is in a plane substantially at right angles to the aXis of the plug; a gland in threaded engagement with the threaded portion aforesaid of said shell and which gland has an end portion of reduced size so arranged relative to said follower as to contact with the upper surface thereof about midway thel width thereof and throughout an annular band or zone of small width as compared with the width of said follower; and a gasket interposed between the ledge aforesaid and the lower of the shoulders of said insulator.

6. In a spark plug of the class described, a hollow metallic shell or casing having a threaded portion adjacent its upper end, and an internal annular ledge located below said threaded portion; an insulator secured in place within said shell and having a lower annular shoulder adapted to overlie said ledge, and an upper shoulder; an annular metallic follower located within said shell and above the upper of the shoulders of said insulator; a. gland nut in threaded engagement with the threaded portion aforesaid of said shell, and the lower end of which gland is in engagement with the upper surface of said follower throughout an annular zone of small width as compared with the width of said upper surface; and a yieldable gasket interposed between the ledge aforesaid and the lower of the shoulders upon said insulator.

In testimony whereof I ailix my signature.

ALBERT oHAMiIoN.

lil() 

